Intervertebral spinal implant

ABSTRACT

An intervertebral implant for implantation in an intervertebral space between vertebrae. The implant includes a body extending from an upper surface to a lower surface. The body has a front end, a rear end and a pair of spaced apart first and second side walls extending between the front and rear walls such that an interior chamber is defined within the front and rear ends and the first and second walls. The body defines an outer perimeter and an inner perimeter extending about the internal chamber. At least one of the side walls is defined by a solid support structure and an integral porous structure, the porous structure extending from the outer perimeter to the inner perimeter. The porous structure embeds or encapsulates at least a portion of the solid support structure.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/973,756 filed on May 8, 2018 which is a continuation of U.S. patentapplication Ser. No. 15/973,609 filed May 8, 2018, which is incorporatedby reference herein in its entirety for all purposes.

FIELD

The present disclosure generally relates to fixation devices and systemsfor positioning and immobilizing at least two adjacent vertebrae andmethods related to the same. In particular, the present disclosurerelates to interbody fusion devices with an integrated solid supportstructure and porous ingrowth structure.

BACKGROUND

The spine is the axis of the skeleton on which all of the body parts“hang”. In humans, the normal spine has seven cervical, twelve thoracicand five lumbar segments. The lumbar spine situs upon the sacrum, whichthen attaches to the pelvis, and in turn is supported by the hip and legbones. The bony vertebral bodies of the spine are separated byintervertebral discs, which act as joints but allow known degrees offlexion, extension, lateral bending, and axial rotation.

The typical vertebra has a thick anterior bone mass called the vertebralbody, with a neural (vertebral) arch that arises from the posteriorsurface of the vertebral body. The central of adjacent vertebrae aresupported by intervertebral discs. The spinal disc and/or vertebralbodies may be displaced or damaged due to trauma, disease, degenerativedefects, or wear over an extended period of time. One result of thisdisplacement or damage to a spinal disc or vertebral body may be chronicback pain. In many cases, to alleviate back pain from degenerated ofherniated discs, the disc is removed along with all or part of at leastone neighboring vertebrae and is replaced by an implant that promotesfusion of the remaining bony anatomy.

However, the success or failure of spinal fusion may depend upon severalfactors. For instance, the spacer or implant or cage used to fill thespace left by the removed disc and bony anatomy must be sufficientlystrong to support the spine under a wide range of loading conditions.The spacer should also be configured so that it likely to remain inplace once it has been positioned in the spine by the surgeon.Additionally, the material used for the spacer should be biocompatiblematerial and should have a configuration that promotes bony ingrowth.

SUMMARY

To meet this and other needs, intervertebral implants for use with theanterior, antero-lateral, lateral, and/or posterior portions of at leastone motion segment unit of the spine, systems, and methods are provided.Traditionally, interbody spacers or implants intended to help facilitateintervertebral fusion may serve as a means to restore intervertebralheight and/or lordosis. The implant may feature a central lumen to housebone graft material. It is through this central lumen where most of thefusion may occur. The implants of the disclosure incorporate avolumetric, interconnected porosity throughout the entire spacer. Thisenables bone to grow into and/or through the spacer, making it part ofthe fusion mass. The incorporation of a volumetric, interconnectedporosity within the implant may encourage faster, strongerintervertebral fusion.

According to one embodiment, a cervical intervertebral implant forimplantation in an intervertebral space between vertebrae is provided.The implant includes a body having a front end, a rear end and opposedside walls extending between the ends. The body has an outer perimeterwith a trapezoidal shape and an inner perimeter about an internalchamber. The body includes an upper surface and a lower surface with theupper surface defined by a solid upper outer rim and a spaced apartsolid upper inner rim and the lower surface defined by a solid lowerouter rim and a spaced apart solid lower inner rim. A solid front wallextends at the front end between at least the solid upper outer rim andthe solid lower outer rim. A solid rear wall extends at the rear endbetween at least the solid upper outer rim and the solid lower outerrim. Each of the side walls includes at least one solid cross strutextending between the solid upper rims and at least one solid crossstrut extending between the solid lower rims. Each of the side wallsincludes at least one solid support structure extending between theupper surface and the lower surface with the solid support structureoccupying a minimal space within each side wall. A porous structure isintegrally formed with the solid upper rims, the solid lower rims, eachof the solid cross struts, and each of the solid structures in each ofthe side walls and extends from the body outer perimeter to the bodyinner perimeter.

According to another embodiment, an intervertebral implant forimplantation in an intervertebral space between vertebrae is provided.The implant includes a body having a front end, a rear end and opposedside walls extending between the ends. The body has an outer perimeterand an inner perimeter about an internal chamber. The body includes anupper surface and a lower surface. The upper surface is defined by asolid upper outer rim and a spaced apart solid upper inner rim and thelower surface is defined by a solid lower outer rim and a spaced apartsolid lower inner rim. A solid front wall extends at the front endbetween at least the solid upper outer rim and the solid lower outerrim. A solid rear wall extends at the rear end between at least thesolid upper outer rim and the solid lower outer rim. Each of the sidewalls includes at least one solid support structure extending betweenthe upper and lower surfaces. A porous structure is integrally formedwith the solid upper rims, the solid lower rims and the at least onesolid support structure in each of the side walls. The porous structureextends from the body outer perimeter to the body inner perimeter whilethe solid upper and lower outer rims and the solid front and rear wallsextend along the outer perimeter such that the porous structure isencased within solid structure.

According to yet another embodiment, a cervical intervertebral implantfor implantation in an intervertebral space between vertebrae isprovided. The implant includes a body extending from an upper surface toa lower surface. The body has a front end, a rear end and a pair ofspaced apart first and second side walls extending between the front andrear walls such that an interior chamber is defined within the front andrear ends and the first and second walls. The body defines an outerperimeter with a trapezoidal shape and an inner perimeter extendingabout the internal chamber. At least one of the walls is defined by asolid support structure and an integral porous structure. The porousstructure extends from the outer perimeter to the inner perimeter andfrom the upper surface to the lower surface and encapsulates at least aportion of the solid support structure.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present disclosure, and theattendant advantages and features thereof, will be more readilyunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings wherein:

FIGS. 1-4 are perspective, side, top and rear views, respectively, of anintervertebral implant according to one embodiment of the disclosurewith the porous portions shown textured;

FIGS. 5-7 are perspective, top and side views, respectively, of theintervertebral implant of FIGS. 1-4 with the porous portions removed toshow the support structure;

FIGS. 8-10 are perspective, top and side views, respectively, of anintervertebral implant according to another embodiment of the disclosurewith the porous portions shown translucently;

FIGS. 11-13 are perspective, top and side views, respectively, of anintervertebral implant according to another embodiment of the disclosurewith the porous portions shown translucently;

FIGS. 14-16 are perspective, top and side views, respectively, of anintervertebral implant according to another embodiment of the disclosurewith the porous portions shown translucently;

FIGS. 17-19 are perspective, top and side views, respectively, of anintervertebral implant according to another embodiment of the disclosurewith the porous portions shown translucently;

FIGS. 20-22 and 24 are perspective, top, side and rear views,respectively, of an intervertebral implant according to anotherembodiment of the disclosure with the porous portions shown textured,and FIG. 23 is a cross-sectional view along the lines 23-23 in FIG. 21;

FIGS. 25-27 are perspective, top and side views, respectively, of theintervertebral implant of FIGS. 20-24 with the porous portions removedto show the support structure;

FIGS. 28-31 are perspective, top, side and rear views, respectively, ofan intervertebral implant according to another embodiment of thedisclosure with the porous portions shown textured;

FIGS. 32-34 are perspective, top and side views, respectively, of theintervertebral implant of FIGS. 28-31 with the porous portions removedto show the support structure;

FIGS. 35 and 36 are perspective and side views, respectively, of anintervertebral implant according to another embodiment of the disclosurewith the porous portions shown translucently;

FIGS. 37 and 38 are rear and side views, respectively, of anintervertebral implant according to another embodiment of the disclosurewith the porous portions shown translucently;

FIG. 39 is a perspective view of an intervertebral implant according toanother embodiment of the disclosure with the porous portions showntranslucently;

FIGS. 40-43 are perspective, top, side and rear views, respectively, ofan intervertebral implant according to another embodiment of thedisclosure with the porous portions shown textured;

FIGS. 44-47 are perspective, top, side and rear views, respectively, ofthe intervertebral implant of FIGS. 40-43 with the porous portionsremoved to show the support structure;

FIGS. 48-51 are perspective, top, side and rear views, respectively, ofan intervertebral implant according to another embodiment of thedisclosure with the porous portions shown translucently;

FIGS. 52 and 53 are perspective and side views, respectively, of anintervertebral implant according to another embodiment of the disclosurewith the porous portions shown translucently;

FIGS. 54-57 are perspective, rear, top and side views, respectively, ofan intervertebral implant according to another embodiment of thedisclosure with the porous portions shown translucently;

FIGS. 58-61 are perspective, top, side and rear views, respectively, ofan intervertebral implant according to another embodiment of thedisclosure with the porous portions shown textured;

FIGS. 62-64 are perspective, top and side views, respectively, of theintervertebral implant of FIGS. 58-61 with the porous portions removedto show the support structure;

FIGS. 65-67 are perspective, top and side views, respectively, of anintervertebral implant according to another embodiment of the disclosurewith the porous portions shown translucently;

FIGS. 68 and 69 are perspective and side views, respectively, of anintervertebral implant according to another embodiment of the disclosurewith the porous portions shown translucently;

FIGS. 70-72 are perspective, top and side views, respectively, of anintervertebral implant according to another embodiment of the disclosurewith the porous portions shown translucently;

FIGS. 73-75 are perspective, top and side views, respectively, of anintervertebral implant according to another embodiment of the disclosurewith the porous portions shown translucently;

FIGS. 76 and 77 are perspective and top views, respectively, of anintervertebral implant according to another embodiment of the disclosurewith the porous portions shown textured;

FIGS. 78 and 79 are perspective and top views, respectively, of anintervertebral implant according to another embodiment of the disclosurewith the porous portions shown textured;

FIGS. 80-83 are front perspective, rear perspective, top and side views,respectively, of the spacer portion of the implants of FIGS. 76-79 withthe porous portions shown textured;

FIGS. 84-86 are perspective, top and side views, respectively, of thespacer portion of FIGS. 80-83 with the porous portions removed to showthe support structure; and

FIGS. 87 and 88 are illustrative photos of various porous structures inaccordance with embodiments of the disclosure;

FIGS. 89-92 are perspective, bottom, side and rear views, respectively,of an intervertebral implant according to another embodiment of thedisclosure with the porous portions shown textured;

FIGS. 93-96 are perspective, bottom, side and rear views, respectively,of the intervertebral implant of FIGS. 89-92 with the porous portionsremoved to show the support structure;

FIGS. 97 and 98 are top and side views, respectively, of anintervertebral implant according to another embodiment of the disclosureand FIG. 99 is a cross-sectional view along the line 99-99 in FIG. 97;

FIGS. 100 and 101 are side views of an intervertebral implant accordingto another embodiment of the disclosure, with FIG. 101 illustrating aninsertion tool extending through the implant;

FIG. 102 is a perspective view of an intervertebral implant according toanother embodiment of the disclosure, FIG. 103 is a cross-sectional viewalong the line 103-103 in FIG. 102 and FIG. 104 is a cross-sectionalview along the line 104-104 in FIG. 102;

FIGS. 105 and 106 are front and perspective views, respectively,illustrating a grid porous configuration;

FIG. 107 is a perspective view of an intervertebral implant according toanother embodiment of the disclosure;

FIG. 108 is a perspective view of an intervertebral implant according toanother embodiment of the disclosure;

FIG. 109 is a side view of an intervertebral implant according toanother embodiment of the disclosure;

FIGS. 110-112 are perspective, side and top views, respectively, of anintervertebral implant according to another embodiment of the disclosureand FIG. 113 is a cross-sectional view along the line 113-113 in FIG.112;

FIGS. 114 and 115 illustrate alternative strut patterns of anillustrative support structure;

FIG. 116 is a perspective view of an intervertebral implant according toanother embodiment of the disclosure;

FIG. 117 is a cross-sectional view of an intervertebral implantaccording to another embodiment of the disclosure;

FIG. 118 is a top view of an intervertebral implant according to anotherembodiment of the disclosure and FIG. 119 is a cross-sectional viewalong the line 119-119 in FIG. 118;

FIGS. 120 and 121 are top and rear views, respectively, of anintervertebral implant according to another embodiment of the disclosureand FIG. 122 is a cross-sectional view along the line 122-122 in FIG.121;

FIG. 123 is a side view of an intervertebral implant according toanother embodiment of the disclosure;

FIGS. 124 and 125 are top and side views, respectively, of anintervertebral implant according to another embodiment of the disclosureand FIG. 126 is a cross-sectional view along the line 126-126 in FIG.124;

FIG. 127 is a side view of an intervertebral implant according toanother embodiment of the disclosure and FIG. 128 is a cross-sectionalview along the line 128-128 in FIG. 127;

FIG. 129 is an exploded side view of an intervertebral implant accordingto another embodiment of the disclosure;

FIGS. 130-132 are top views showing sequentially implantation of anexpandable intervertebral implant according to another embodiment of thedisclosure;

FIGS. 133 and 134 are front and top views, respectively, of anintervertebral implant according to another embodiment of the disclosureand FIG. 135 is a cross-sectional view along the line 135-135 in FIG.134;

FIG. 136 is a perspective view illustrating an example tool hole andFIG. 137 is a cross-sectional view illustrating a toll engaged in such ahole;

FIG. 138 is a schematic view of an example delivery tool in accordancewith an embodiment of the disclosure;

FIGS. 139-141 are perspective, top and side views, respectively, of anintervertebral implant according to another embodiment of the disclosurewith the porous portions shown textured; and

FIGS. 142 and 143 are perspective and top views, respectively, of theintervertebral implant of FIGS. 139-141 with the porous portions removedto show the support structure.

DETAILED DESCRIPTION

Embodiments of the disclosure are generally directed to intervertebralimplants, systems, and method of use thereof. The implant may besuitable for use with the anterior, antero-lateral, lateral, and/orposterior portions of at least one motion segment unit of the spine.Traditionally, interbody spacers or implants intended to help facilitateintervertebral fusion may serve as a means to restore intervertebralheight and/or lordosis. The implants may feature a central lumen tohouse bone graft material, for example. It is through this central lumenwhere most of the fusion may occur. The implants of the disclosure mayincorporate a volumetric, interconnected porosity throughout the entirespacer or a portion thereof. This enables bone to growth into and/orthrough the spacer or a portion thereof, making it part of the fusionmass. The incorporation of a volumetric, interconnected porosity mayencourage faster, stronger intervertebral fusion, thereby providing forbetter patient outcomes.

Various forms of additive manufacturing, or 3D printing, have beendeveloped which allow structures to be formed layer by layer. Oneillustrative 3D printing technology is Direct Metal Laser Sintering(DMLS) wherein parts are built using a laser to selectively sinter (heatand fuse) a powdered metal material into layers. The process begins oncea 3D CAD file is mathematically sliced into multiple 2D cross sectionsand uploaded into the system. After the first layer is produced, thebuild platform is lowered, another powder layer is spread across theplate, and the laser sinters the second layer. This process is repeateduntil the part is complete. Layer-by-layer manufacturing allows for thedirect fabrication of complex parts that would be cost-prohibitive, andoften impossible, to produce through traditional manufacturingprocesses. The powder layer thickness used during the fabrication of thespacers may be as thin at 30 μm. The resolution of the laser may be asfine as 70 μm. Although it is envisioned that any suitable thickness orlaser resolution may be used or selected.

The disclosure is not limited to DMLS, but various 3D printing methodsmay be utilized. For example, VAT Photopolymerization utilizes a vat ofliquid photopolymer resin which is cured through selective exposure tolight (via a laser or projector) which then initiates polymerization andconverts the exposed areas to a solid part. As another example, PowderBed Fusion, of which DMLS is a subcategory, utilizes powdered materialswhich are selectively consolidated by melting it together using a heatsource such as a laser or electron beam. The powder surrounding theconsolidated part acts as support material for overhanging features. Asyet another example, in Binder Jetting Liquid bonding agents areselectively applied onto thin layers of powdered material to build upparts layer by layer. The binders include organic and inorganicmaterials. Metal or ceramic powdered parts are typically fired in afurnace after they are printed. Material Jetting is another example of a3D printing process which may be utilized wherein droplets of materialare deposited layer by layer to make parts. Common varieties includejetting a photocurable resin and curing it with UV light, as well asjetting thermally molten materials that then solidify in ambienttemperatures. As another example, in Sheet Lamination sheets of materialare stacked and laminated together to form an object. The laminationmethod can be adhesives or chemical (paper/plastics), ultrasonicwelding, or brazing (metals). Unneeded regions are cut out layer bylayer and removed after the object is built. Another example of a 3Dprinting process that may be utilized is Material Extrusion whereinmaterial is extruded through a nozzle or orifice in tracks or beads,which are then combined into multi-layer models. Common varietiesinclude heated thermoplastic extrusion and syringe dispensing. Yetanother example is Directed Energy Deposition wherein powder or wire isfed into a melt pool which has been generated on the surface of the partwhere it adheres to the underlying part or layers by using an energysource such as a laser or electron beam.

The implants of the disclosure may be manufactured from any of these orother additive manufacturing processes currently known or laterdeveloped. The implants may also be manufactured utilizing a combinationof additive manufacturing processes and other manufacturing processes,for example, laser etching. Additionally, the implants may be furtherprocessed during and/or after manufacture utilizing various techniques,for example, abrasion, machining, polishing, or chemical treatment. Theimplants may be manufactured from various materials, such asbiocompatible materials, including metals, polymers, ceramics orcombinations thereof. Exemplary materials include Titanium (and Titaniumalloys), Cobalt-Chrome, PEEK, and/or Stainless Steel, for example.

As will be discussed in more detail hereinafter, the implants of thedisclosure generally comprise a solid support structure and a porousstructure formed integral therewith. The solid support structure mayinclude solid front and rear walls interconnected by upper and lowerimplant surfaces. The upper and lower surfaces may include spaced apartrims with cross struts interconnecting the rims. In many embodiments,the solid support structure of the upper and lower surfaces includes aplurality of openings in which the integral porous structure is formedsuch that the porous structure extends along at least a portion of theupper and lower implant surfaces. The side walls extending between thefront and rear walls generally have a minimal solid structure, forexample, a plurality of struts extending between the upper and lowerrims, but otherwise have open area therebetween in which the integralporous structure is formed. The configuration of the solid structure isselected to provide the implant sufficient structural integrity andmechanical stability while maximizing the area of porous structure whichfacilitates better integration/incorporation with the adjacent bone. Inseveral embodiments of the disclosure, the solid structure generallyencases the corners of the porous structure or otherwise houses theporous structure therein to maintain the structural integrity of theporous structure.

Referring now to FIGS. 1-7, one embodiment of a cervical intervertebralimplant 10 will be described. As illustrated, the implant 10 has a body11 with a generally trapezoidal shape. The body 11 is defined by atapered front end 12, a rectangular rear end 14 and side walls 16 and 18extending therebetween. The implant 10 has an outer perimeter OPextending about the body 11. A hollow interior chamber 13 is definedwithin an inner perimeter IP of the body 11. The hollow interior chamber13 is configured to receive bone growth promoting materials, forexample. The implant 10 has an upper surface 20 and a lower surface 22,with both surfaces having a tapering portion 23 at the front end 12. Theupper and lower surfaces 20, 22 may be substantially parallel orotherwise configured to provide the proper intervertebral spacing. Theupper and lower surfaces 20, 22 define a plurality of serrations 24along the side walls 16, 18 and a plurality of serrations 26 along therear end 14. The serrations 24, 26 are defined by both the solid supportstructure 30 and the porous structure 50. As will be described in detailhereinafter, the solid support structure 30 includes spaced apart rims32, 34 and 36, 38 with cross struts 31 and 37. The solid supportstructure 30 defines open spaces or recesses adjacent the cross struts31, 37 and the porous structure 50 is formed within such open spacessuch that the solid structure 30 and the porous structure 50 togetherform the serrations 24, 26. As illustrated in FIGS. 1-4, the porousstructure 50 extends to and forms a portion of the implant upper andlower surfaces 20-22. The rear end 14 of the implant 10 includes a hole25 and a pair of blind slots 27 for receiving an instrument that is usedfor inserting the implant 10. As seen in FIGS. 1-4, the implant 10 isdefined by a solid support structure 30 with an interfiled, integralporous structure 50.

The solid support structure 30 will be described in more detail withreference to FIGS. 5-7. An outer rim 32 extends about the outerperimeter OP of the upper surface 20 and an inner rim 34 extends aboutthe inner perimeter IP of the upper surface 20, i.e. about the interiorchamber 13. Similarly, an outer rim 36 extends about the outer perimeterOP of the lower surface 22 and an inner rim 38 extends about the innerperimeter IP of the lower surface 22. A plurality of cross struts 31extend between the outer rims 32, 36 and the respective inner rims 34,38 along the side wall areas. As seen in the figures, the cross struts31 along with contoured portions 33 of the rims 32, 34, 36, 38 definethe contour of the serrations 24. In addition to interconnecting therims within a given upper or lower surface, struts 44, 46 and 48 extendwithin each side wall area to interconnect the upper rims 32, 34 withthe lower rims 36, 38. In the illustrated embodiment, a first strut 44extends from the lower inner rim 38 to the upper outer rim 32 near therear portion of the support structure 30, a second strut 46 extends fromthe lower inner rim 38 to the upper outer rim 32 near the front portionof the support structure 30 and an X-shaped strut 48 extends betweenboth lower rims 36, 38 and both upper rims 32, 34 at a central locationof the support structure 30. As can be seen in FIGS. 6 and 7, each ofthe first struts 44 extends from the lower inner rim 38 proximate therear wall 35 at an angle to approximately the midpoint of the upperouter rim 32, substantially tangent to the curvature of the inner rims34, 38. Similarly, each of the second struts 46 extends from the lowerinner rim 38 proximate the front wall 40 at an angle to approximatelythe midpoint of the upper outer rim 32, substantially tangent to thecurvature of the inner rims 34, 38. Each of the X-shaped struts 48extends substantially parallel to the upper and lower rims andpositioned at the point where the first and second struts 44, 46 meetwith the upper outer rim 36. The struts may have other configurationsand more or fewer struts may be utilized.

The solid rear wall 35 additionally interconnects the outer rims 32, 36and the respective inner rims 34, 38 along the rear end area as well asfurther connecting the upper and lower structures together. The solidrear wall 35 defines the hole 25 and slots 27. Recessed areas 39 and 41on the upper and lower sides of the rear wall 35 define receiving areasfor porous structure, as seen in FIGS. 1-4. Cross members 37 in thisarea along with contours of the outer rims 32, 36 define the serrations26. The solid front wall 40 has a concave configuration and alsointerconnects the outer rims 32, 36 and the respective inner rims 34, 38along the front end area. The front wall 40 includes an upper slopedportion 42 extending between the upper outer rim 32 and inner rim 34 anda lower sloped portion 43 extending between the lower outer rim 36 andinner rim 38. While the rims and walls are described as specificelements for clarity, it is understood that the elements are formed as aunitary structure and may be formed as a smooth structure without anydistinction between the elements.

In the illustrations of the support structure 30 shown in FIGS. 5-7 withthe porosity omitted for illustration, it is seen that there issignificant open space between the upper rims 32, 34 and the lower rims36, 38 with only the struts 44, 46, 48 therebetween. The struts 44, 46,48 occupy only a minimal space between the upper and lower rims 32, 34,36, 38, for example, less than 50% of the wall space, thereby leavingsubstantial open space for the porous structure 50. Additionally, thereis open space between the inside surface of the front wall 40 and theinner rims 34, 38. Furthermore, there is open space on an inside surfaceand the recesses 39, 41 of the rear wall 35. As illustrated in FIGS.1-4, in the implant 10, these open spaces are filled with the porousstructure 50 such that the porous structure 50 encapsulates the struts44, 46, 48 and extends from the upper surface 20 to the lower surface 22and from the outer perimeter OP to the inner perimeter IP. In theillustrated embodiment, the porous structure 50 substantially definesthe inner perimeter IP and defines a substantial portion of the sidewalls 16, 18 along the outer perimeter OP.

The configuration of the support structure 30 and the porous structure50 are selected, for example, to provide the implant with an adequateconstruct strength while maximizing the potential for bony in-growth andallowing for clear radiographic imaging. Referring to FIGS. 87 and 88,the porous structure 50 may have a randomized pattern of open pores 50 aor a repeating pattern of open pores 50 b. The porous structure 50 mayhave a suitable porosity (open volume). For example, the porousstructure 50 may be greater than 50% open, greater than 60% open,greater than 70% open, or approximately 70% open, or approximately 75%open. The porous structure 50 may feature interconnected pores or openpores. The porous structure 50 may have pores, for example, ranging fromapproximately 100 μm-2 mm, approximately 100 μm-1 mm, approximately200-900 μm, or approximately 300-800 μm in diameter. The pore size mayhave an average pore size of about 300-800 μm, about 400-700 μm, orabout 500-600 μm. The pore size distribution may be unimodal orbi-modal. Although spherical or partially-spherical pores or nodes areexemplified in forming the porous structure, it is envisioned that othersuitable pore shapes and configurations may be used, for example,repeating or random patterns of cylinders, cubes, cones, pyramids,polyhedrons, or the like.

It is contemplated that different areas of the support structure 30 mayhave varying stiffness or strength, for example, variable A-P stiffnessto achieve optimized load on an anterior graft or to achieve a desiredlevel of flexibility within the implant 10. Furthermore, the porousstructure 50 may have different porosities or densities in differentareas of the implant 10. For example, the porous structure 50 may have ahigher porosity or density along the inner perimeter compared to that atthe outer perimeter, for example, with the inner area having acancellous porosity and the outer area having a cortical porosity. Theporous structure 50 may have various configurations, for example, a gridor honeycomb pattern which may promote bony in-growth. Additionally, theporous structure 50 may be configured such that when it is turned past acritical angle it may appear opaque, thereby helping with assessment ofthe implant orientation or positioning. The surface texture of both thesupport structure and the porous structure may be controlled to provideboth macro and micro texturizing. The features and characteristicsdescribed with respect to this embodiment may be incorporated in any ofthe embodiments described herein. Additionally, features described inany of the embodiments herein may be incorporated into any of the otherembodiments.

Referring now to FIGS. 8-10, a cervical intervertebral implant 10′ inaccordance with another embodiment of the disclosure will be described.The implant 10′ is similar to the previous embodiment except for aslight modification in the structure of the support structure 30′ and acorresponding modification in the porous structure 50′. Compared to theprevious embodiment, the rear wall 35′ has a narrower width with aportion of the rear end 14′ having an open support structure into whichthe porous structure 50′ extends. With the narrower width, the recessesportions 39′, 41′ open directly into the open space of the side walls16′, 18′ and rear end 14′. To maintain sufficient implant strength, apair of X-shaped struts 48′, 48″ are positioned in each of the side wallareas 16′, 18′ proximate the rear end 14′ of the implant 10′. While thefront end 12 of the implant 10′ remains substantially the same as in theprevious embodiment, an additional X-shaped strut 48′″ is p positionedin each of the side wall areas 16′, 18′ proximate the rear end 14′ ofthe implant 10′. Again, in the implant 10′, the open spaces are filledwith the porous structure 50′ such that the porous structure 50′encapsulates the struts 44, 46, 48, 48′, 48″, 48′″ and extends from theupper surface 20 to the lower surface 22 and from the outer perimeter OPto the inner perimeter IP. In the illustrated embodiment, the porousstructure 50′ substantially defines the inner perimeter IP and defines asubstantial portion of the side walls 16′, 18′ and a portion of the rearend 14′ along the outer perimeter OP.

Referring now to FIGS. 11-13, a cervical intervertebral implant 10″ inaccordance with another embodiment of the disclosure will be described.The implant 10″ is similar to the previous embodiment except for slightmodification in the structure of the support structure 30″ and acorresponding modification in the porous structure 50″. In the presentembodiment, the struts within the side walls are replaced with externalX-shaped struts 60, 62. Outer X-shaped struts 60 extend along each ofthe side walls 16″, 18″ along the outer perimeter OP. The outer X-shapedstruts 60 extend between the upper and lower outer rims 32 and 36. InnerX-shaped struts 62 extend along each of the side walls 16″, 18″ alongthe inner perimeter IP. The inner X-shaped struts 62 extend between theupper and lower inner rims 34 and 38. A generally hollow wall space isdefined between the outer and inner X-shaped struts 60, 62 on the sidesand the cross struts 31, 37 on the top and bottom. These hollow wallspaces extend from the front wall 40 to the rear wall 35′ and are filledwith the integral porous structure 50″. Again, in the implant 10″, theopen spaces are filled with the porous structure 50″ such that itextends from the upper surface 20 to the lower surface 22 and from theouter perimeter OP to the inner perimeter IP. In the present embodiment,the struts 60, 62 are not encapsulated in the porous structure 50″, butinstead the struts 60 are coplanar with the porous structure 50″ alongthe outer perimeter OP and the struts 62 are coplanar with the porousstructure 50″ along the inner perimeter IP. Again, the porous structure50″ substantially defines the inner perimeter IP and defines asubstantial portion of the side walls 16″, 18″ and a portion of the rearend 14′ along the outer perimeter OP.

Referring now to FIGS. 14-16, a cervical intervertebral implant 10′″ inaccordance with another embodiment of the disclosure will be described.The implant 10′″ is similar to the previous embodiment except for slightmodification in the structure of the support structure 30′″ and acorresponding modification in the porous structure 50′″. In the presentembodiment, the external X-shaped struts 60′, 62′ have a narrowerconfiguration and have curved portions compared to those of the previousembodiment. Again, outer X-shaped struts 60′ extend along each of theside walls 16″, 18″ along the outer perimeter OP as they extend betweenthe upper and lower outer rims 32 and 36. Inner X-shaped struts 62′extend along each of the side walls 16″, 18″ along the inner perimeterIP as they extend between the upper and lower inner rims 34 and 38. Inthe present embodiment, in the rear area 14″ of the implant 10″', therear wall 35″ is not connected to the upper or lower rim 32, 36 andinstead open spaces 61 extend therebetween. As in the previousembodiment, a generally hollow wall space is defined between the outerand inner X-shaped struts 60′, 62′ on the sides and the cross struts 31,37 on the top and bottom. These hollow wall spaces extend from the frontwall 40 to the rear wall 35″ and are filled with the integral porousstructure 50′″. As in the previous embodiments, all of the open spacesof the implant 10′″ are filled with the porous structure 50′″ such thatit extends from the upper surface 20 to the lower surface 22 and fromthe outer perimeter OP to the inner perimeter IP. As in the previousembodiment, the struts 60′, 62′ are not encapsulated in the porousstructure 50′″, but instead the struts 60′ are coplanar with the porousstructure 50′″ along the outer perimeter OP and the struts 62′ arecoplanar with the porous structure 50′″ along the inner perimeter IP.Again, the porous structure 50′″ substantially defines the innerperimeter IP and defines a substantial portion of the side walls 16″,18″ and a portion of the rear end 14″ along the outer perimeter OP.

Referring now to FIGS. 17-19, a cervical intervertebral implant 10 ^(iv)in accordance with another embodiment of the disclosure will bedescribed. The implant 10 ^(iv) is similar to the previous embodimentexcept for slight modification in the structure of the support structure30 ^(iv) and a corresponding modification in the porous structure 50^(iv). In the present embodiment, the struts are replaced with aninternal corrugated wall 64 within each of the side walls 16′″, 18′″.Each corrugated wall 64 extends between the upper support structure andthe lower support structure. In the illustrated embodiment, eachcorrugated wall 64 extends from the front wall 12, interconnects withthe cross struts 31, 37 and interconnects with the rear wall 35′″. Inthe present embodiment, in the rear area 14″ of the implant 10′″, openspaces 61 extend between the rear wall 35′″ and the upper or lower rims32, 36 as in the previous embodiment, however, additional supports 63extend between the upper rims 32, 34 and the rear wall 35′″ and betweenthe lower rims 36, 38 and the rear wall 35′″. As in the previousembodiments, all of the open spaces of the implant 10 ^(iv) are filledwith the porous structure 50 ^(iv) such that it extends from the uppersurface 20 to the lower surface 22. The porous structure 50 ^(iv) of thepresent embodiment encapsulates each corrugated wall 64 and while theporous structure 50 ^(iv) is not continuous from the outer perimeter OPto the inner perimeter IP, the porous structure 50 ^(iv) stillsubstantially defines the inner perimeter IP and defines a substantialportion of the side walls 16″, 18″ and a portion of the rear end 14″along the outer perimeter OP.

Referring now to FIGS. 20-27, one embodiment of an anterior lumbarinterbody fusion (ALIF) implant 110 will be described. As illustrated,the implant 110 has a body 111 with a generally D-shaped configuration.The body 111 is defined by a tapered front end 112, a rectangular rearend 114 and side walls 116 and 118 extending therebetween. The implant110 has an outer perimeter OP extending about the body 111. A hollowinterior chamber 113 is defined within an inner perimeter IP of the body111. The hollow interior chamber 113 is configured to receive bonegrowth promoting materials. The implant 110 has an upper surface 120 anda substantially parallel lower surface 122, with both surfaces having atapering portion 123 at the front end 112. The upper and lower surfaces120, 122 define a plurality of serrations 124 along the side walls 116,118 and a plurality of serrations 126 along the rear end 114. The rearend 114 of the implant 110 includes a plurality of screw holes 125through which screws (not shown) extend to anchor the implant onto thevertebral body. Secondary holes 127 are provided to receive respectiveblocking set screws (not shown). A threaded hole 128 and a blind slot129 are provided for receiving an instrument that is used for insertingthe implant 110. As seen in FIGS. 20-24, the implant 110 is defined by asolid support structure 130 with an interfiled, integral porousstructure 150.

The solid support structure 130 will be described in more detail withreference to FIGS. 25-25. An outer rim 132 extends about the outerperimeter OP of the upper surface 120 and an inner rim 134 extends aboutthe inner perimeter IP of the upper surface 120, i.e. about the interiorchamber 113. Similarly, an outer rim 136 extends about the outerperimeter OP of the lower surface 122 and an inner rim 138 extends aboutthe inner perimeter IP of the lower surface 122. A plurality of crossstruts 131 extend between the outer rims 132, 136 and the respectiveinner rims 134, 138 along the side wall areas. As seen in the figures,the cross struts 131 along with contoured portions 133 of the rims 132,134, 136, 138 define the contour of the serrations 124. In addition tointerconnecting the rims within a given upper or lower surface, struts144, 146 extend within each side wall area to interconnect the upperrims 132, 134 with the lower rims 136, 138. In the illustratedembodiment, a first multi-leg strut 144 extends from the lower inner rim138 to the upper outer rim 132 near the rear portion of the supportstructure 130 and a second multi-leg strut 146 extends from the lowerinner rim 138 to the upper outer rim 132 near the front portion of thesupport structure 130.

A solid rear wall 135 additionally interconnects the outer rims 132, 136and the respective inner rims 134, 138 along the rear end area as wellas further connecting the upper and lower structures together. The solidrear wall 135 defines the holes 125, 127, 128 and the slot 129. Recessedareas 139 on the upper and lower sides of the rear wall 135 definereceiving areas for porous structure, as seen in FIGS. 20-24. Crossmembers 137 in this area along with contours of the outer rims 132, 136define the serrations 126. A solid front wall 140 with a concaveconfiguration also interconnects the outer rims 132, 136 and therespective inner rims 134, 138 along the front end area. The front wall140 includes an upper sloped portion 142 extending between the upperouter rim 132 and inner rim 134 and a lower sloped portion 143 extendingbetween the lower outer rim 136 and inner rim 138. While the rims andwalls are described as specific elements for clarity, it is understoodthat the elements are formed as a unitary structure and may be formed asa smooth structure without any distinction between the elements.

In the illustrations of the support structure 130 in FIGS. 25-27, it isseen that there is significant open space between the upper rims 132,134 and the lower rims 136, 138 with only the struts 144, 146therebetween. Additionally, there is open space between the insidesurface of the front wall 140 and the inner rims 134, 138. Furthermore,there is open space on an inside surface and the recesses 139, 141 ofthe rear wall 135. As illustrated in FIGS. 20-24, in the implant 110,these open spaces are filled with the porous structure 150 such that theporous structure 150 encapsulates the struts 144, 146 and extends fromthe upper surface 120 to the lower surface 122 and from the outerperimeter OP to the inner perimeter IP. In the illustrated embodiment,the porous structure 150 substantially defines the inner perimeter IPand defines a substantial portion of the side walls 116, 118 along theouter perimeter OP.

Referring now to FIGS. 28-34, an ALIF implant 110′ in accordance withanother embodiment of the disclosure will be described. The implant 110′is similar to the previous embodiment except for slight modification inthe structure of the support structure 130′ and a correspondingmodification in the porous structure 150′. Compared to the previousembodiment, the upper and lower surfaces 120′, 122′ of the presentimplant 110′ are angled relative to one another. Additionally, the rearwall 135′ has a narrower width with a portion of the rear end 114′having an open support structure into which the porous structure 150′extends. With the narrower width, the recess portions 139′ open directlyinto the open space of the side walls 116′, 118′ and rear end 114′. Therear wall 135′ defines a single opening 128′ for receipt of an insertiontool. A cylinder 145 is positioned between the upper rims 132, 136 andthe lower rims 134, 138 along the rear end 114′. The cylinder 145defines a through bore 147 configured to also receive an insertion tool.To maintain sufficient implant strength in the rear end 114′, a firstX-shaped struts 148 extends between the cylinder 145 and the end wall135′ and a second X-shaped strut 148′ is positioned on the opposite sideof the rear wall 135. The front end 112 of the implant 110′ includes arecessed area 141 which defines a forward serration 149. Again, in theimplant 110′, the open spaces are filled with the porous structure 150′such that the porous structure 150′ encapsulates the struts 144, 146,114, 148′ and extends from the upper surface 120′ to the lower surface122′ and from the outer perimeter OP to the inner perimeter IP. In theillustrated embodiment, the porous structure 150′ substantially definesthe inner perimeter IP and defines a substantial portion of the sidewalls 116′, 118′ and a portion of the rear end 114′ along the outerperimeter OP.

Referring now to FIGS. 35 and 36, an ALIF implant 110″ in accordancewith another embodiment of the disclosure will be described. The implant110″ is similar to the previous embodiment except for slightmodification in the structure of the support structure 130″ and acorresponding modification in the porous structure 150″. Compared to theprevious embodiment, the rear wall 135″ of the rear end 114″ includes aplurality of slots 129′ positioned about the hole 128′. Additionally,the struts of the previous embodiment are replaced with a plurality ofX-shaped struts 152 which are interconnected to one another by acircumferential intermediate rim 154. Each of the struts 152 alsointerconnects with the upper rims 132, 136 and the lower rims 134, 137.Again, in the implant 110″, the open spaces are filled with the porousstructure 150″ such that the porous structure 150″ encapsulates thestruts 152 and the intermediate rim 154 and extends from the uppersurface 120′ to the lower surface 122′ and from the outer perimeter OPto the inner perimeter IP. In the illustrated embodiment, the porousstructure 150″ substantially defines the inner perimeter IP and definesa substantial portion of the side walls 116′, 118′ and a portion of therear end 114″ along the outer perimeter OP.

Referring now to FIGS. 37 and 38, an ALIF implant 110′″ in accordancewith another embodiment of the disclosure will be described. The implant110′″ is similar to the previous embodiment except for slightmodification in the structure of the support structure 130″ and acorresponding modification in the porous structure 150″. Compared to theprevious embodiment, the X-shaped struts are replaced by coil struts 156a and 156 b. Coil strut 156 a of side wall area 118′ extends from therear wall 135″ to the front wall 140″ and extends about thecircumferential intermediate rim 154. Similarly, coil strut 156 b ofside wall area 116′ extends from the rear wall 135″ to the front wall140″ and extends about the circumferential intermediate rim 154,however, the cylinder 145 extends through and interconnects with thecoil strut 154 b. Each of the struts 156 a, 156 b also interconnectswith the upper rims 132, 136 and the lower rims 134, 137. Again, in theimplant 110′″, the open spaces are filled with the porous structure150′″ such that the porous structure 150′″ encapsulates the intermediaterim 154 and struts 156 a, 156 b and extends from the upper surface 120′to the lower surface 122′ and from the outer perimeter OP to the innerperimeter IP. In the illustrated embodiment, the porous structure 150′″substantially defines the inner perimeter IP and defines a substantialportion of the side walls 116′, 118′ and a portion of the rear end 114″along the outer perimeter OP.

Referring now to FIG. 39, an ALIF implant 110 ^(iv) in accordance withanother embodiment of the disclosure will be described. The implant 110^(iv) has a body 111′ with a generally oval configuration. The body 111′is defined by a tapered front end 112″, a rectangular rear end 114′″ andside walls 116″ and 118″ extending therebetween. The implant 110 ^(iv)has an outer perimeter OP extending about the body 111′. A hollowinterior chamber 113 is defined within an inner perimeter IP of the body111′. The hollow interior chamber 113 is configured to receive bonegrowth promoting materials. The implant 110 ^(iv) has an upper surface120′ and a substantially parallel lower surface 122′, with both surfaceshaving a tapering portion 123 at the front end 112. In the presentembodiment, each of the surfaces 120′, 122′ includes a central surfaceportion 175. The upper and lower surfaces 120′, 122′ define a pluralityof serrations 124′ along the side walls 116, 118 and the centralportions 175 and a plurality of serrations 126′ along the rear end114′″. The rear end 114′″ of the implant 110 includes a plurality ofholes 128″, 145 configured for receiving an instrument that is used forinserting the implant 110. As in the previous embodiments, the implant110 ^(iv) is defined by a solid support structure 130 ^(iv) with aninterfiled, integral porous structure 150 ^(iv).

The solid support structure 130 ^(iv) includes an upper plate 160extending from the front end 112″ to the rear end 114′″ and definingside wall portions 162, 164 and central portion 166. A plurality ofrecesses 173 in the upper and lower plates 160, 170 are filled with theporous structure 150 ^(iv) to define the serrations 124′, 126′.Similarly, a lower plate 170 extends from the front end 112″ to the rearend 114′″ and defines side wall portions 172, 174 and central portion176. The upper and lower plates 160, 170 are interconnected by a frontwall 140″ and a rear wall 135″. It is noted that in the presentembodiment, the side walls 116′, 118′ are generally open without anysupport structure and completely filled with the porous structure 150^(iv). The rear wall 135″ defines the holes 128″, 145. The rear wall135″ includes a plurality of recesses 171 configured to receive theporous structure 150 ^(iv). As in the previous embodiments, the porousstructure 150 ^(iv) generally extends from the upper surface 120′ to thelower surface 122′ and from the outer perimeter OP to the innerperimeter IP. In the illustrated embodiment, the porous structure 150^(iv) substantially defines the inner perimeter IP and defines asubstantial portion of the side walls 116′, 118′ along the outerperimeter OP.

Referring now to FIGS. 40-47, one embodiment of a transforaminal lumbarinterbody fusion (TLIF) implant 210 will be described. As illustrated,the implant 210 has a body 211 with a generally rectangular shape. Thebody 211 is defined by a tapered front end 212, a rectangular rear end214 and side walls 216 and 218 extending therebetween. The implant 210has an outer perimeter OP extending about the body 211. A hollowinterior chamber 213 is defined within an inner perimeter IP of the body211. The hollow interior chamber 213 is configured to receive bonegrowth promoting materials. The implant 210 has an upper surface 220 anda substantially parallel lower surface 222, with both surfaces having atapering portion 223 at the front end 212. The upper and lower surfaces220, 222 define a plurality of serrations 224 along the side walls 216,218 and a plurality of serrations 226 along the rear end 214. The rearend 214 of the implant 210 includes a hole 225 and a pair of slots 227for receiving an instrument that is used for inserting the implant 210.The implant 210 is defined by a solid support structure 230 with aninterfiled, integral porous structure 250.

The solid support structure 230 includes an outer rim 232 extendingabout the outer perimeter OP of the upper surface 220 and an inner rim234 extending about the inner perimeter IP of the upper surface 220,i.e. about the interior chamber 213. Similarly, an outer rim 236 extendsabout the outer perimeter OP of the lower surface 222 and an inner rim238 extends about the inner perimeter IP of the lower surface 222. Aplurality of cross struts 231 extend between the outer rims 232, 236 andthe respective inner rims 234, 238 along the side wall areas. As seen inthe figures, the cross struts 231 along with contoured portions 233 ofthe rims 232, 234, 236, 238 define the contour of the serrations 224. Inaddition to interconnecting the rims within a given upper or lowersurface, external radial struts 260, 262 additionally interconnect therims 232, 234, 236, 238. Outer radial struts 260 extend along each ofthe side walls 216, 218 along the outer perimeter OP. The outer radialstruts 260 have a central portion 261 and legs 263 which extend betweenthe upper and lower outer rims 232 and 236. Inner radial struts 262extend along each of the side walls 216, 218 along the inner perimeterIP. The inner radial struts 262 have a central portion 265 and legs 267which extend between the upper and lower inner rims 234 and 238.

A solid rear wall 235 additionally interconnects the outer rims 232, 236and the respective inner rims 234, 238 along the rear end area as wellas further connecting the upper and lower structures together. The solidrear wall 235 defines the hole 225 and slots 227. Recessed areas 239 and241 on the upper and lower sides of the rear wall 235 define receivingareas for porous structure, as seen in FIGS. 40-43. The contours of theouter rims 232, 236 define the serrations 226. A solid front wall 240with a concave configuration also interconnects the outer rims 232, 236and the respective inner rims 234, 238 along the front end area. Thefront wall 240 includes an upper sloped portion 242 extending betweenthe upper outer rim 232 and inner rim 234 and a lower sloped portion 243extending between the lower outer rim 236 and inner rim 238. While therims and walls are described as specific elements for clarity, it isunderstood that the elements are formed as a unitary structure and maybe formed as a smooth structure without any distinction between theelements.

In the illustrations of the support structure 230 in FIGS. 44-47, it isseen that there is significant open space between the upper rims 232,234 and the lower rims 236, 238, between the inside surface of the frontwall 240 and the inner rims 234, 238, and on an inside surface and therecesses 239, 241 of the rear wall 235. As illustrated in FIGS. 40-43,in the implant 210, the open spaces are filled with the porous structure250 such that it extends from the upper surface 220 to the lower surface222 and from the outer perimeter OP to the inner perimeter IP. In thepresent embodiment, the struts 260, 262 are not encapsulated in theporous structure 250, but instead the struts 260 are coplanar with theporous structure 250 along the outer perimeter OP and the struts 262 arecoplanar with the porous structure 250 along the inner perimeter IP.Again, the porous structure 250 substantially defines the innerperimeter IP and defines a substantial portion of the side walls 216,218 along the outer perimeter OP.

Referring now to FIGS. 48-51, a TLIF implant 210′ in accordance withanother embodiment of the disclosure will be described. The implant 210′is similar to the previous embodiment except for slight modification inthe structure of the support structure 230′ and a correspondingmodification in the porous structure 250′. In the present embodiment, aconnecting ring 268 interconnects the central portion 261 with thecentral portion 265 of the struts 260, 262 in each side wall 216, 218.Additionally, on the upper and lower surfaces 220, 222, additionalserrations 229 are provided adjacent the rear end 214′. Again, in theimplant 210′, the open spaces are filled with the porous structure 250′such that it extends from the upper surface 220 to the lower surface 222and from the outer perimeter OP to the inner perimeter IP. In thepresent embodiment the struts 260 are coplanar with the porous structure250′ along the outer perimeter OP and the struts 262 are coplanar withthe porous structure 250′ along the inner perimeter IP. The connectingrings 268 are encapsulated within the porous structure 250′. Again, theporous structure 250′ substantially defines the inner perimeter IP anddefines a substantial portion of the side walls 216, 218 along the outerperimeter OP.

Referring now to FIGS. 52 and 53, a TLIF implant 210″ in accordance withanother embodiment of the disclosure will be described. The implant 210″is similar to the embodiment illustrated in FIGS. 40-47 except forslight modification in the structure of the support structure 230″ and acorresponding modification in the porous structure 250″. In the presentembodiment, in addition to the struts 260, 262, a plurality of X-shapedstruts 244 extend between the upper rims 232, 234 and the lower rims236, 238 in each side wall 216, 218. Again, in the implant 210″, theopen spaces are filled with the porous structure 250″ such that itextends from the upper surface 220 to the lower surface 222 and from theouter perimeter OP to the inner perimeter IP. In the present embodimentthe struts 260 are coplanar with the porous structure 250′ along theouter perimeter OP and the struts 262 are coplanar with the porousstructure 250′ along the inner perimeter IP. The X-shaped struts 244 areencapsulated within the porous structure 250″. Again, the porousstructure 250″ substantially defines the inner perimeter IP and definesa substantial portion of the side walls 216, 218 along the outerperimeter OP.

Referring now to FIGS. 52 and 53, a TLIF implant 210′″ in accordancewith another embodiment of the disclosure will be described. The implant210′″ is similar to the embodiment illustrated in FIGS. 40-47 except forslight modification in the structure of the support structure 230′″ anda corresponding modification in the porous structure 250′″. In thepresent embodiment, the side walls 216′, 218′ do not include externalstruts, but instead include a plurality of X-shaped struts 246 extendingbetween the upper rims 232, 234 and the lower rims 236, 238 in each sidewall 216′, 218′. Additionally, an intermediate plate 248 interconnectsthe X-shaped struts 246 within each side wall area. Again, in theimplant 210′″, the open spaces are filled with the porous structure250′″ such that the porous structure 250′″ encapsulates the struts 246and the intermediate plate 248 and extends from the upper surface 220 tothe lower surface 222 and from the outer perimeter OP to the innerperimeter IP. In the illustrated embodiment, the porous structure 250′″substantially defines the inner perimeter IP and defines a substantialportion of the side walls 216′, 218′ along the outer perimeter OP.

Referring now to FIGS. 58-64, one embodiment of a lateral lumbarinterbody fusion (LLIF) implant 310 will be described. As illustrated,the implant 310 has a body 311 with a generally rectangular shape. Thebody 311 is defined by a tapered front end 312, a rectangular rear end314 and side walls 316 and 318 extending therebetween. The implant 310has an outer perimeter OP extending about the body 311. A hollowinterior chamber 313 is defined within an inner perimeter IP of the body311. The hollow interior chamber 313 is configured to receive bonegrowth promoting materials. The implant 310 has an upper surface 320 anda substantially parallel lower surface 322, with both surfaces having atapering portion 323 at the front end 312. The upper and lower surfaces320, 322 define a plurality of serrations 324 along the side walls 316,318, a serration 328 along the front end 312 and a plurality ofserrations 326 along the rear end 314. The illustrated serrations 324,326, 328 have micro serrations defined thereon. The rear end 314 of theimplant 310 includes a hole 325 surrounded by a slot 327 for receivingan instrument that is used for inserting the implant 310. The implant310 is defined by a solid support structure 330 with an interfiled,integral porous structure 350.

Referring to FIGS. 62-64, the solid support structure 330 includes anouter rim 332 extending about the outer perimeter OP of the uppersurface 320 and an inner rim 334 extending about the inner perimeter IPof the upper surface 320, i.e. about the interior chamber 313.Similarly, an outer rim 336 extends about the outer perimeter OP of thelower surface 322 and an inner rim 338 extends about the inner perimeterIP of the lower surface 322. A plurality of cross struts 331 extendbetween the outer rims 332, 336 and the respective inner rims 334, 338along the side wall areas. As seen in the figures, the cross struts 331along with contoured portions 333 of the rims 332, 334, 336, 338 definethe contour of the serrations 324. In addition to interconnecting therims within a given upper or lower surface, a plurality of X-shapedstruts 344 extend within each side wall area to interconnect the upperrims 332, 334 with the lower rims 336, 338.

A solid rear wall 335 additionally interconnects the outer rims 332, 336and the respective inner rims 334, 338 along the rear end area as wellas further connecting the upper and lower structures together. The solidrear wall 335 defines the hole 325 and slot 327. A portion of the rearwall 335 defining the hole 325 extends to a secondary rear wall 360which extends between the upper and lower inner rims 334, 338. A crossstrut 339 on the upper and lower sides of the rear wall 335 and aportion of the rear wall 335 define the serrations 326. A solid frontwall 340 also interconnects the outer rims 332, 336 and a secondaryfront wall 362 interconnects the inner rims 334, 338 along the front endarea. The front wall 340 includes an upper sloped portion 342 extendingbetween the upper outer rim 332 and inner rim 334 and a lower slopedportion 343 extending between the lower outer rim 336 and inner rim 338.While the rims and walls are described as specific elements for clarity,it is understood that the elements are formed as a unitary structure andmay be formed as a smooth structure without any distinction between theelements. A portion of the front wall 340 defines the serration 328.

In the illustrations of the support structure 330 in FIGS. 62-64, it isseen that there is significant open space between the upper rims 332,334 and the lower rims 336, 338, between the inside surface of the frontwall 340 and the secondary wall 362 and on an inside surface of the rearwall 335. As illustrated in FIGS. 58-61, in the implant 310, the openspaces are filled with the porous structure 350 such that itencapsulates the struts 344 and extends from the upper surface 320 tothe lower surface 322 and from the outer perimeter OP to the innerperimeter IP. In the illustrated embodiment, the porous structure 350substantially defines the inner perimeter IP and defines a substantialportion of the side walls 316, 318 along the outer perimeter OP.

Referring now to FIGS. 65-67, an LLIF implant 310′ in accordance withanother embodiment of the disclosure will be described. The implant 310′is similar to the previous embodiment except for slight modification inthe structure of the support structure 330′ and a correspondingmodification in the porous structure 350′. Compared to the previousembodiment, the cross struts 331′ and 339′ do not includemini-serrations. Additionally, the rear wall 335′ has a narrower widthwith a portion of the rear end 314′ having an open support structureinto which the porous structure 350′ extends. The front end 312 of theimplant 310′ includes a cylindrical portion 364 extending between thefront wall 340 and the secondary front wall 362. Again, in the implant310′, the open spaces are filled with the porous structure 350′ suchthat the porous structure 350′ encapsulates the struts 344 and extendsfrom the upper surface 320 to the lower surface 322 and from the outerperimeter OP to the inner perimeter IP. In the illustrated embodiment,the porous structure 350′ substantially defines the inner perimeter IPand defines a substantial portion of the side walls 316′, 318′ along theouter perimeter OP.

Referring now to FIGS. 68 and 69, an LLIF implant 310″ in accordancewith another embodiment of the disclosure will be described. The implant310″ is similar to the previous embodiment except for slightmodification in the structure of the support structure 330″ and acorresponding modification in the porous structure 350″. Compared to theprevious embodiment, the upper rims 332′, 334′ and lower rims 336′, 338′each have a wider configuration and do not have cross struts extendingtherebetween. The serrations 324′, 326′, 328′ are formed directly on therims 332′, 334′, 336′, 338′, on the rear wall 335′ and the front wall340′. Additionally, the struts 344 are interconnected to one another bya circumferential intermediate rim 365. Again, in the implant 310″, theopen spaces are filled with the porous structure 350″ such that theporous structure 350″ encapsulates the struts 344 and intermediate rim365 and extends from the upper surface 320 to the lower surface 322 andfrom the outer perimeter OP to the inner perimeter IP. In theillustrated embodiment, the porous structure 350″ substantially definesthe inner perimeter IP and defines a substantial portion of the sidewalls 316″, 318″ along the outer perimeter OP.

Referring now to FIGS. 70-72, an LLIF implant 310′″ in accordance withanother embodiment of the disclosure will be described. The implant310′″ is similar to the embodiment illustrated in FIGS. 65-67 except forslight modification in the structure of the support structure 330′″ anda corresponding modification in the porous structure 350′″. Compared tothe embodiment illustrated in FIGS. 65-67, the rims 332, 334, 336, 338do not have cross struts extending therebetween. Additionally, externalstruts 366 are provided along the outside perimeter OP along each sidewall 316′″, 318′″ and external struts 368 are provided along the insideperimeter IP along each side wall 316′″, 318′″. Again, in the implant310′″, the open spaces are filled with the porous structure 350′″ suchthat the porous structure 350′″ encapsulates the struts 344 and extendsfrom the upper surface 320 to the lower surface 322 and from the outerperimeter OP to the inner perimeter IP. The struts 366 are coplanar withthe porous structure 350′″ along the outer perimeter OP and the struts368 are coplanar with the porous structure 350′″ along the innerperimeter IP. In the illustrated embodiment, the porous structure 350′″substantially defines the inner perimeter IP and defines a substantialportion of the side walls 316′″, 318′″ along the outer perimeter OP.

Referring now to FIGS. 73-75, an LLIF implant 310 ^(iv) in accordancewith another embodiment of the disclosure will be described. The implant310 ^(iv) is similar to the previous embodiment except for slightmodification in the structure of the support structure 330 ^(iv) and acorresponding modification in the porous structure 350 ^(iv). Comparedto the previous embodiment, the rims 332, 334, 336, 338 have crossstruts 331′ extending therebetween but do not include X-shaped strutswithin the side walls 316 ^(iv), 318 ^(iv). Again, in the implant 310^(iv), the open spaces are filled with the porous structure 350 ^(iv)such that the porous structure 350 ^(iv) extends from the upper surface320 to the lower surface 322 and from the outer perimeter OP to theinner perimeter IP. The struts 366 are coplanar with the porousstructure 350 ^(iv) along the outer perimeter OP and the struts 368 arecoplanar with the porous structure 350 ^(iv) along the inner perimeterIP. In the illustrated embodiment, the porous structure 350 ^(iv)substantially defines the inner perimeter IP and defines a substantialportion of the side walls 316 ^(iv), 318 ^(iv) along the outer perimeterOP.

Referring now to FIGS. 139-143, an LLIF implant 310 ^(v) in accordancewith another embodiment of the disclosure will be described. The implant310 ^(v) is similar to the embodiment illustrated in FIGS. 58-64 exceptfor slight modification in the structure of the support structure 330^(v) and a corresponding modification in the porous structure 350 ^(v).In the present embodiment, the implant body 311′ has a wedgeconfiguration, tapering from a thickest height along the outer edge ofthe side wall 318 ^(v) to a thinnest height along the outer edge of theside wall 316 ^(v). The front wall 340″ and rear wall 335″ arecorrespondingly tapered. Additionally, the serration 328″ along thefront wall 340″ does not include micro serrations. As in the embodimentillustrated in FIGS. 58-64, the rims 332, 334, 336, 338 have crossstruts 331 extending therebetween, but do not include X-shaped strutswithin the side walls 316 ^(v), 318 ^(v). Instead, each side wall 316^(v), 318 ^(v) has a single linear strut 369 extending perpendicularlybetween the upper outer rim 332 and the lower outer rim 336 at anapproximate mid-point of the side wall 316 ^(v), 318 ^(v). Again, in theimplant 310 ^(v), the open spaces are filled with the porous structure350 ^(v) such that the porous structure 350 ^(v) extends from the uppersurface 320 to the lower surface 322 and from the outer perimeter OP tothe inner perimeter IP. The struts 369 are coplanar with the porousstructure 350 ^(v) along the outer perimeter OP. In the illustratedembodiment, the porous structure 350 ^(v) substantially defines theinner perimeter IP and defines a substantial portion of the side walls316 ^(v), 318 ^(v) along the outer perimeter OP.

Referring now to FIGS. 76-86, embodiments of two-piece cervical implants400, 400′ will be described. Each of the implants 400, 400′ includes aplate 402, 402′ and connectable spacer 410. Each of the plates 402, 402′defines bone screw holes 403 and one or more blocking set screws 404.The plates 402, 402′ may have varying configurations with tabs 405 andprojections 406. The plate configurations are not limited to thoseshown. Each of the plates 402, 402′ includes arms 407 with inwardprojections 408 which engage in slots 419 in the spacer 410 to connectthe spacer 410 with the respective plate 402, 402′. The illustratedplates 402, 402′ are solid structures and do not include porousstructure, however, the plates may be made with portions having a porousstructure.

Referring to FIGS. 80-86, the spacer 410 has body 411 with a generallyU-shaped configuration. The body 411 is defined by a tapered front end412 with side walls 416 and 418 extending to free ends 414 a, 414 b. Thespacer 410 has an outer perimeter OP extending about the body 411 and aninner perimeter IP within the U-shape of the body 411. When the spacer410 is connected with a plate 402, 402′, a hollow interior chamber 413is defined which is configured to receive bone growth promotingmaterials. The spacer 410 has an upper surface 420 and a substantiallyparallel lower surface 422, with both surfaces having a tapering portion423 at the front end 412. The upper and lower surfaces 420, 422 define aplurality of serrations 424 along the side walls 416, 418, a serration428 along the front end 412 and serrations 426 at the free ends 414 a,414 b. Each side wall 416, 418 defines a connection slot 419 forward ofthe respective free end 414 a, 414 b. The slots 419 are engaged by theprojections 408 on the plate arms 407 to attach the spacer 410 to therespective plate 402, 402′. The spacer 410 is defined by a solid supportstructure 430 with an interfiled, integral porous structure 450.

Referring to FIGS. 84-86, the solid support structure 430 includes anouter rim 432 extending about the outer perimeter OP of the uppersurface 420 and an inner rim 434 extending about the inner perimeter IPof the upper surface 420. Similarly, an outer rim 436 extends about theouter perimeter OP of the lower surface 422 and an inner rim 438 extendsabout the inner perimeter IP of the lower surface 422. A plurality ofcross struts 431 extend between the outer rims 432, 436 and therespective inner rims 434, 438 along the side wall areas. As seen in thefigures, the cross struts 431 along with contoured portions 433 of therims 432, 434, 436, 438 define the contour of the serrations 424.

A solid front wall 440 interconnects the outer rims 432, 436 along thefront end area. The front wall 440 includes an upper sloped portion 442and a lower sloped portion 443. While the rims and walls are describedas specific elements for clarity, it is understood that the elements areformed as a unitary structure and may be formed as a smooth structurewithout any distinction between the elements. A portion of the frontwall 440 defines the serration 428. A rear wall structure 435 a, 435 bat each free end 414 a, 414 b additionally interconnects the outer rims432, 436 and the respective inner rims 434, 438 along the rear end areaas well as further connecting the upper and lower structures together.The rear wall structure 435 a extends about an open area 460 with a sideopening 462 and rear wall structure 435 b extends about an open area 464with opposed side openings 465, 466.

In the illustrations of the support structure 430 in FIGS. 84-86, it isseen that there is significant open space between the upper rims 432,434 and the lower rims 436, 438, between the inside surface of the frontwall 440 and the inner rims 434, 438 and within the open areas 460, 462.As illustrated in FIGS. 80-83, in the spacer 410, the open spaces arefilled with the porous structure 450 such that it extends from the uppersurface 420 to the lower surface 422 and from the outer perimeter OP tothe inner perimeter IP. In the illustrated embodiment, the porousstructure 450 substantially defines the inner perimeter IP and defines asubstantial portion of the side walls 416, 418 along the outer perimeterOP.

Referring now to FIGS. 89-96, an embodiment of an articulating TLIFimplant 510 will be described. As illustrated, the implant 510 has abody 511 with a generally arcuate shape. The body 511 is defined by atapered front end 512, a rectangular rear end 514 and arcuate side walls516 and 518 extending therebetween. The implant 510 has an outerperimeter OP extending about the body 511. A hollow interior chamber 513is defined within an inner perimeter IP of the body 511. The hollowinterior chamber 513 is configured to receive bone growth promotingmaterials. The implant 510 has an upper surface 520 and a substantiallyparallel lower surface 522, with both surfaces having a tapering portion523 at the front end 512. The upper and lower surfaces 520, 522 define aplurality of serrations 524 along the side walls 516, 518 and aplurality of serrations 526 along the rear end 514. The rear end 514 ofthe implant 510 includes a hole 525 through one of the surfaces 522 anda slot 527 in communication therewith. An articulating member 570 ispositioned within the hole 525 and slot 527 and is pivotal relative tothe body 511. The articulating member 570 includes a body 572 receivedin and rotatable within the hole 525. A threaded tool receiving opening574 extends from the body 572 and is aligned within the slot 527. Athreaded implant tool is received in the threaded tool receiving opening574 and may be utilized for implanting and articulating the position ofthe implant 510 in a known manner. The articulating member 570 may bemanufactured during the 3D manufacturing process of the body 511 or maybe manufactured separately and thereafter positioned within the body511. The implant 510 is defined by a solid support structure 530 with aninterfiled, integral porous structure 550.

The solid support structure 530 includes an outer rim 532 extendingabout the outer perimeter OP of the upper surface 520 and an inner rim534 extending about the inner perimeter IP of the upper surface 520,i.e. about the interior chamber 513. Similarly, an outer rim 536 extendsabout the outer perimeter OP of the lower surface 522 and an inner rim538 extends about the inner perimeter IP of the lower surface 522. Aplurality of cross struts 531 extend between the outer rims 532, 536 andthe respective inner rims 534, 538 along the side wall areas. As seen inthe figures, the cross struts 531 along with contoured portions 533 ofthe rims 532, 534, 536, 538 define the contour of the serrations 524. Inaddition to interconnecting the rims within a given upper or lowersurface, external linear struts 560, 562 additionally interconnect therims 532, 534, 536, 538. An outer linear strut 560 extends along each ofthe side walls 516, 518 along the outer perimeter OP. The outer linearstruts 560 extend substantially perpendicular to the upper and lowerrims at an approximate midpoint of the respective wall. An inner linearstrut 562 extends along each of the side walls 516, 518 along the innerperimeter IP. The inner linear struts 562 extend substantiallyperpendicular to the upper and lower rims at an approximate midpoint ofthe respective wall.

The solid rear wall 535 additionally interconnects the outer rims 532,536 and the respective inner rims 534, 538 along the rear end area aswell as further connecting the upper and lower structures together. Thesolid rear wall 535 defines the hole 525 and slots 527. Recessed areas539 and 541 on the upper and lower sides of the rear wall 535 extendbetween the cross struts 537 and define the serrations 526, however, inthe present embodiment, these recesses generally do not receive porousstructure, as seen in FIGS. 89-92. It is understood that these recessescould receive porous structure as in previous embodiments. The solidfront wall 540 also interconnects the outer rims 532, 536 and therespective inner rims 534, 538 along the front end area. The front wall540 includes an upper sloped portion 542 extending between the upperouter rim 532 and inner rim 534 and a lower sloped portion 543 extendingbetween the lower outer rim 536 and inner rim 538. While the rims andwalls are described as specific elements for clarity, it is understoodthat the elements are formed as a unitary structure and may be formed asa smooth structure without any distinction between the elements.

In the illustrations of the support structure 530 in FIGS. 93-96, it isseen that there is significant open space between the upper rims 532,534 and the lower rims 536, 538 and between the inside surface of thefront wall 540 and the inner rims 534, 538. As illustrated in FIGS.89-92, in the implant 510, the open spaces are filled with the porousstructure 550 such that it extends from the upper surface 520 to thelower surface 522 and from the outer perimeter OP to the inner perimeterIP. In the present embodiment, the struts 560, 562 are not encapsulatedin the porous structure 550, but instead the struts 560 are coplanarwith the porous structure 550 along the outer perimeter OP and thestruts 562 are coplanar with the porous structure 550 along the innerperimeter IP. Again, the porous structure 550 substantially defines theinner perimeter IP and defines a substantial portion of the side walls516, 518 along the outer perimeter OP.

Referring to FIGS. 97-99, another embodiment of an intervertebralimplant 600 will be described. The implant 600 includes an upper plate602 and a lower plate 604 supported by a plurality of solid struts 606,608 extending therebetween. An open graft window 605 is defined withinthe implant 600. The struts 606, 608 are configured to provide desiredload bearing properties of the implant 600. The end plates 602, 604 maybe formed as a porous structure, for example, having a trabecularporosity. In addition to the porosity, the surfaces of the end plates602, 604 may have a nanoscale roughness formed thereon. As seen in FIG.98, in the illustrated embodiment, the end plates 602, 604 and thestruts 606, 608 are configured such that the implant 600 has a biconvexsuperior and inferior geometry.

Referring to FIGS. 100 and 101, another embodiment of an intervertebralimplant 610 will be described. The implant 610 includes an upper plate612 and a lower plate 614 supported by X-shaped struts 616 extendingbetween the plates 612, 614 on each lateral side of the implant 610. Anopen graft window 615 is defined within the implant 610 between theplates 612, 614. As shown in FIG. 101, the window 615 may be configuredto receive an insertion tool 618. The end plates 602, 604 and struts 616may be formed as a porous structure. Alternatively, the struts 616 maybe formed as a solid structure. In addition to the porosity, thesurfaces of the end plates 612, 614 may have a roughness 613 formedthereon.

Referring to FIGS. 102-106, another embodiment of an intervertebralimplant 620 will be described. The implant 620 includes an upper plate622 and a lower plate 624 supported by opposed solid walls 616, 618extending therebetween. Anterior and/or lateral windows 621 open into aninterior chamber 623 configured to receive graft material. Each of theupper and lower plates 622, 624 has a central open area 625 wherein aporous webbing surface 627 is formed. FIGS. 105 and 106 illustrateexamples of a porous webbing surface 627. The webbing may be formed witha grid or honeycomb pattern which is porous to bone ingrowth. Thewebbing may also be configured such that is may appear opaque whenturned past a critical angle. Such a feature may be used for assessingthe implants orientation or position.

Referring to FIGS. 107 and 108, intervertebral implants 630, 640illustrating various features will be described. The implant 630 of FIG.107 includes a body 632 with an upper surface 634 and a lower surface636. One or both of the surfaces 634, 636 may be formed with a complexconfiguration to optimize end plate contact. For example, the uppersurface 634 has a biconcave configuration. Similarly, the implant 640 ofFIG. 108 includes a body 642 with an upper surface 644 and a lowersurface 646. One or both of the surfaces 644, 646 may be formed withvarious teeth or surface roughness features to minimize subsidence ormigration. For example, the upper surface 646 has a plurality of teeth648 defined thereon. For each of the implants 630, 640, the body 632,642 may include both solid structure and porous structure as describedherein.

Referring to FIG. 109, another embodiment of an intervertebral implant650 will be described. The implant 650 includes an upper plate 652 and alower plate 654 supported by a plurality of solid struts 656 extendingtherebetween. The density of the struts 656 increases moving posteriorlyto provide a varying A-P stiffness to the implant, for example, tooptimize the load of an anterior graft.

Referring to FIGS. 110-113, another embodiment of an intervertebralimplant 660 will be described. The implant 660 includes an upper surface662 and a lower surface 664 supported by a plurality of solid struts 666extending therebetween. The upper and lower surfaces 662, 664 aredefined by perimeter struts 667 and diagonal struts 668. As illustrated,the struts 666, 667, 668 that make up the support structure extendgenerally along the supporting edges while the remainder of the implantstructure remains open for either porous structure or ingrowth chambers.FIGS. 114 and 115 illustrate alternative strut configurations for eitherthe side walls or top or bottom surfaces of the implant 650. In theembodiment illustrated in FIG. 114, the struts 666′, 668′ have arectangular central region with radial supports extending from thecorners thereof. In the embodiment illustrated in FIG. 115, the struts666″, 668″ have a diamond shaped central region with octagon patternedstruts thereabout.

Referring to FIG. 116, another embodiment of an intervertebral implant670 will be described. The implant 670 includes a body 671 with an uppersurface 672 and a lower surface 672 extending about an opening 613 intoan ingrowth cavity. The front end of the implant 670 includes slopedsurfaces 675 to define a smooth leading edge. One or both of thesurfaces 672, 672 may include a radial sawtooth configuration 676. As inprevious embodiments, the body 671 may include both solid structure andporous structure as described herein.

Referring to FIG. 117, another embodiment of an intervertebral implant680 will be described. The implant 680 includes a solid support frame682 encased within porous structure 684, 686. The implant 680 defines atleast one opening 681 into an ingrowth chamber 683. In the illustratedembodiment, the porous structure includes areas of different densities.In the illustrated embodiment, the outer porous structure 684 has alower density than the inner porous structure 686. As described herein,the various implants may be formed with porous structures having varyingdensities, not just with respect to outer and inner layers, but alsowithin a given layer at different areas of the implant, e.g. anteriorversus posterior.

Referring to FIGS. 118 and 119, another embodiment of an intervertebralimplant 690 will be described. The implant 690 includes a body 692extending about an ingrowth chamber 693. The body 692 is defined by aporous portion 696 surrounding a plurality of support struts 694. Thesupport struts 694 are not interconnected to one another. The supportstruts 694 may be a solid structure or may be a porous structure with agreater density than the porous portion 696. For example, the struts 694may be a porous structure having a cancellous density while the porousstructure 696 has a cortical density. Since the body 692 includes asignificant porous structure, the ingrowth chamber 693 may be smallerthan compared to an implant having a non-porous body.

Referring to FIGS. 120-122, another embodiment of an intervertebralimplant 700 will be described. The implant 700 includes a body 702 withan ingrowth pocket 703 extending into the posterior side thereof. Thebody 702 is defined by a porous portion 706 surrounding a plurality ofsupport struts 704. The support struts 704 are not interconnected to oneanother. The support struts 704 may be a solid structure or may be aporous structure with a greater density than the porous portion 706. Forexample, the struts 704 may be a porous structure having a cancellousdensity while the porous structure 706 has a cortical density.

Referring to FIG. 123, another embodiment of an intervertebral implant710 will be described. The implant 710 includes a body 712. The body 712is defined by an external area of higher density porous structure 714surrounding a less dense porous structure 716. The higher density porousstructure 714 acts as struts to provide the implant 710 strength. Thearea of higher density porous structure 714 is shown in a zig zagpattern, but may have other patterns and configurations.

Referring to FIGS. 124-126, another embodiment of an intervertebralimplant 720 will be described. The implant 720 includes an upper plate722 and a lower plate 724. Each of the plates 722 and 724 has a waveconfiguration with minimum struts 726 interconnecting the plates 722,724. With such a configuration, the implant 720 has spring between theplates. An open graft window 723 is defined within the implant 720. Theplates 722, 724 and the struts 726 may include both solid structure andporous structure, as described herein.

Referring to FIGS. 127 and 128, another embodiment of an intervertebralimplant 730 will be described. The implant 730 includes a body 732surrounding an ingrowth chamber 733. The body 732 is defined by a porousportion 734 which is surrounded a continuously wrapped support rib 736.The support rib 736 may be a solid structure or may be a porousstructure with a greater density than the porous portion 734.

Referring to FIG. 129, another embodiment of an intervertebral implant740 will be described. The implant 740 includes interconnectable bodyportions 742 and 744. In the illustrated embodiment, the upper bodyportion 742 includes a post 743 configured to friction fit within a hole745 of the lower body portion 744. Various interconnectable upper andlower body portions 742, 744 may be printed and interconnected to form acustomized implant 740. In the illustrated embodiment, three additionallower body portions 744′, 744″, 744′″ and provided and all may beinterconnected with the upper body portion 742 to achieve implantshaving different configurations.

Referring to FIGS. 130-132, another embodiment of an intervertebralimplant 750 and a method of implantation thereof will be described. Theimplant 750 includes a central body 752 and a pair of expandable wings753, 755. The implant 750 is connected to a hollow insertion tool 756and moved within an intervertebral space 759. Once in position, graftmaterial 757 is fed through the tool 756 and into the implant 750whereby the wings 753, 755 are caused to expand. Graft material 757 issupplied until the area within the central body 752 and the expandedwings 753, 755 is filled. The packed graft material 757 maintains theexpanded configuration of the implant 750.

Referring to FIGS. 133-135, another embodiment of an intervertebralimplant 760 and a method of inserting such implant will be described.The implant 760 includes a body 762 extending about an ingrowth chamber763. The body 762 is generally defined by a porous structure 764. Solidbore holes 766 are defined within the body 762 and are configured toreceive screws or other anchors to facilitate fixation of the implant760. The body 762 also defines a tool receiving opening 765. In theillustrated embodiment, an expandable tool 770 is inserted through theopening 765. The expandable tool 770 includes a pair of legs 772 withflanges 773 on the end thereof. In a collapsed condition, the flanges773 pass through the opening 765. To engage the implant 760, a needle775 or the like is extended between the legs 772, thereby forcing theflanges 773 outward such that the engaged the inside surface of theimplant and do not pass through the opening 765 until the needle 775 isremoved.

Referring to FIGS. 136 and 137, another tool and implant openinginterconnection assembly will be described. In the present embodiment,the implant 780 has a tool receiving opening 782 with a wider centralregion 783 and narrower end regions 784. The insertion tool 790 has ahead 792 with a complimentary configuration. The head 792 is positionedwithin the opening 782 with the orientation of the head 792 matchingthat of the opening 782 such that the head 792 passes through theopening 782. Once inside, the tool head 792 is rotated, for example, aquarter turn, such that the tool head 792 engages the inside surface ofthe implant 780 and is no longer removable through the opening 782. Asecuring sleeve 794 is threadably advanced along the tool 790 andengages the outside surface of the implant 780, securing the implant 780between the tool head 792 and the sleeve 794.

Referring to FIG. 138, another tool and implant opening interconnectionassembly will be described. In the present embodiment, the implant 800has a tool receiving opening 802 with an outward taper 803 at the innerside of the opening 802. The insertion tool 810 has an outer hollow tube812 with a collet 814 on the free end thereof and an inner hollow tube816 with a through passage 817. The inner hollow tube 816 is axiallymovable relative to the outer hollow tube 812. Initially, the innerhollow tube 816 is withdrawn into the outer hollow tube 812 such that itis clear of the collet 814 such that the collet 814 may collapse andpass through the implant opening 802. Once the collet 814 passes throughthe opening 802, the inner hollow tube 816 is moved forward such thatthe collet 814 is expanded outward and maintained in the outwardposition, engaging the tapered portion 803 of the implant opening 802.Graft material or the like may be passed into the implant 800 throughthe through passage 817.

As described herein, the implants of the disclosure generally comprise asolid or higher density support structure and a porous structure formedintegral therewith. The solid support structure may include solid frontand rear walls interconnected by upper and lower implant surfaces. Inseveral of the embodiments, the upper and lower surfaces include spacedapart rims with cross struts interconnecting the rims. In manyembodiments, the solid support structure of the upper and lower surfacesincludes a plurality of openings in which the integral porous structureis formed such that the porous structure extends along at least aportion of the upper and lower implant surfaces. The side wallsextending between the front and rear walls generally have a minimalsolid structure, for example, a plurality of struts extending betweenthe upper and lower rims, but otherwise have open area therebetween inwhich the integral porous structure is formed. The configuration of thesolid structure is selected to provide the implant sufficient structuralintegrity and mechanical stability while maximizing the area of porousstructure which facilitates better integration/incorporation with theadjacent bone. In several embodiments of the disclosure, the solidstructure generally encases the corners of the porous structure orotherwise houses the porous structure therein to maintain the structuralintegrity of the porous structure.

Although the invention has been described in detail and with referenceto specific embodiments, it will be apparent to one skilled in the artthat various changes and modifications can be made without departingfrom the spirit and scope of the invention. Thus, it is intended thatthe invention covers the modifications and variations of this inventionprovided they come within the scope of the appended claims and theirequivalents. It is expressly intended, for example, that all rangesbroadly recited in this document include within their scope all narrowerranges which fall within the broader ranges. It is also intended thatthe components of the various devices disclosed above may be combined ormodified in any suitable configuration.

What is claimed is:
 1. An intervertebral implant for implantation in anintervertebral space between vertebrae, the implant comprising: au-shaped body having a front end, a rear end and opposed side wallsextending between the ends, the body having an outer perimeter and aninner perimeter about an internal chamber, the body comprising: an uppersurface and a lower surface, the upper surface defined by a upper outerrim and a spaced apart upper inner rim and the lower surface defined bya lower outer rim and a spaced apart lower inner rim; a front wallextending at the front end between at least the upper outer rim and thelower outer rim; a rear wall extending at the rear end between at leastthe upper outer rim and the lower outer rim; each of the side wallsincluding at least one cross strut extending between the upper rims andat least one cross strut extending between the lower rims; each of theside walls including at least one support structure extending betweenthe upper surface and the lower surface, the support structure occupyinga minimal space within each side wall; and a porous structure integrallyformed with the upper rims, the lower rims, each of the cross struts,and each of the structures in each of the side walls; and a platemember, the plate member configured to be coupled to the body tocomplete the inner perimeter about the internal chamber.
 2. Theintervertebral implant of claim 1, wherein each of the cross strutsdefines a portion of a surface serration.
 3. The intervertebral implantof claim 1, wherein surface serrations are defined along the upper andlower surfaces along the rear end.
 4. The intervertebral implant ofclaim 1, wherein the support structure within each wall is defined by aplurality of struts.
 5. The intervertebral implant of claim 4, whereinat least one of the struts extends from at least one of the upper rimsto at least one of the lower rims.
 6. The intervertebral implant ofclaim 5, wherein the at least one of the struts extends from the innerrim of one of the upper or lower surfaces to the outer rim of the otherof the upper or lower surfaces.
 7. The intervertebral implant of claim6, wherein the at least one of the struts is embedded within the porousstructure.
 8. The intervertebral implant of claim 5, wherein the atleast one of the struts has an X-shaped configuration.
 9. Theintervertebral implant of claim 8, wherein each of the X-shaped strutsextends perpendicular within the respective wall is embedded within theporous structure.
 10. The intervertebral implant of claim 8, whereineach of the X-shaped struts extends substantially parallel with therespective wall and extends along either outer perimeter or the innerperimeter.
 11. The intervertebral implant of claim 1, wherein thesupport structure within each wall is defined by a corrugated wall. 12.The intervertebral implant of claim 1, wherein the front end includes aexternal concave wall with a portion of the porous structure extendingbetween the concave wall and the inner perimeter.
 13. The intervertebralimplant of claim 1, wherein the rear end is defined substantially by awall.
 14. The intervertebral implant of claim 1, wherein the rear end isdefined in part by a wall and in part by the porous structure withportions of the support structure embedded in the porous structuredefining a part of the rear end.
 15. The intervertebral implant of claim1, wherein porous structure extends between adjacent cross struts. 16.An intervertebral implant for implantation in an intervertebral spacebetween vertebrae, wherein said implant comprises: a u-shaped bodyhaving a front end, a rear end and opposed side walls extending betweenthe ends, the body having an outer perimeter and an inner perimeterabout an internal chamber, the body comprising: an upper surface and alower surface, the upper surface defined by a upper outer rim and aspaced apart upper inner rim and the lower surface defined by a lowerouter rim and a spaced apart lower inner rim; a front wall extending atthe front end between at least the upper outer rim and the lower outerrim; a rear wall extending at the rear end between at least the upperouter rim and the lower outer rim; each of the side walls including atleast one support structure extending between the upper and lowersurfaces; and a porous structure integrally formed with the upper rims,the lower rims and the at least one support structure in each of theside walls, the porous structure extending from the body outer perimeterto the body inner perimeter, the upper and lower outer rims and thefront and rear walls extending along the outer perimeter such that theporous structure is encased within structure; and a plate member, theplate member configured to be coupled to the body to complete the innerperimeter about the internal chamber.
 17. The intervertebral implant ofclaim 16, wherein the support structure includes one or more crossstruts extending between the upper rim members and one or more crossstruts extending between the lower rim members.
 18. The intervertebralimplant of claim 17, wherein each of the cross struts defines a portionof a surface serration.
 19. The intervertebral implant of claim 17,wherein porous structure extends between adjacent cross struts.